San Francisco Police Department provides free access to a great data source: https://data.sfgov.org/browse?category=Public+Safety. The following couple of charts display drug-related incident distribution by year, weekday, time of day, and district.

Some observations:

the notorious "welfare Wednesday" effect is present in early years;

incident numbers drop significantly starting 2010, which may be caused by Proposition 215: Wikipedia says "It was not until March 2009 that federal officials announced that they would no longer try to thwart medical marijuana distribution/use in California".

Tuesday, August 15, 2017

It took me a while to find and groom WHO spending numbers. All financial reports I used can be found here. There were a few challenges, here are some worth mentioning.

1. Between 2000 and 2011, the WHO published two-year financial reports, and in 2012, they switched to one-year schedule.

2. The list of expenditure categories was changing from year two year. As a result, I could not break down equipment and supplies category into meaningful groups, so medical supplies and furniture fall into the same category. Same with the "Other" category: it includes grants, research contracts, local subsidies and what not.

Tuesday, August 8, 2017

I have just came across a blog featuring high-quality charts visualizing all kinds of data: https://datasoaring.blogspot.com. Charts are made with plot.ly, highcharts, bokeh, charte.ca and other tools. Some charts are published as high-quality animated GIFs. Apparently, the blogger uses this data format as a last resort - not so many tools out there support animation right out of the box. Anyways, good to see charte.ca in a good company.

Why log scale? There are a few cases when a log scale is appropriate. The most well known is: log scales allow a large range to be displayed without small values being compressed down into bottom of the graph. Consider the same visualization made using linear scale (this is just a screenshot, not an interactive chart, but it gives you a good idea about the problem):

Tuesday, August 1, 2017

World Bank Group provides a lot of data to play with. Let's build a motion chart based on export, import, and GDP data for European top 20 economies, grouped by regions - Northern, Western, Eastern, and Southern.

Monday, July 31, 2017

charte.ca now supports motion charts. Motion charts are basically bubble charts with one more dimension added (usually, it's time). In charte.ca, we use category for this dimension, remember category radio buttons in charte.ca pie charts and bar charts? So, our motion charts are bubble charts with category radio buttons.

Thursday, June 29, 2017

While Canadians looking for the ultimate party to celebrate Canada's 150th birthday on July 1, we will have a quick look at their spending habits. And we will do that by using charte.ca new feature - animated categories.

Chart options panels went through some reorganization. Now we have "Current category label" panel:

and "Animation" panel:

For charts with multiple data rows that are considered categories (pie, regular bar and comparative histogram charts), charte.ca can walk through all categories and update the appearance, creating an animation effect - see chart below.

Try it for yourself - create a pie, regular bar or comparative histogram chart with multiple data rows and play with animation settings. The feature comes handy when you embed charte.ca visualization into a presentation and do not have a convenient way to click or hover over the chart to navigate between categories.

Thursday, June 1, 2017

Great news: charte.ca charts are now fully scalable. Content editors and users can change the size of the container - the chart will scale accordingly, preserving the original aspect ratio, without losing any functionality or quality.

Tuesday, May 23, 2017

charte.ca integration API comes handy when you want your published chart to display up-to-date information and you do not have the luxury of logging in to the editor, tweaking the data and re-publishing the chart manually every time the data changes. Consider the following P/E ratio vs. Price to book bubble chart that we want to be updated every hour:

Tuesday, May 9, 2017

Users want to have the ability to tweak number formatting. No, users need this feature. Just imagine having labels like "1382323332" and "1340152688" on a diagram comparing Chinese and Indian population. Or imagine a US GDP chart with a "$20000000000000" mark on the vertical axis. Or imagine that your audience wants to see negative amounts of some specific currency: "-£349.3300".

Since the rules of number formatting can be complicated, we decided not to invent our own mechanism for it. We just use the standard instead: ECMAScript Internationalization API Specification. It's a long specification, but the part that we are interested in boils down to this Mozilla document. This document defines how Javascript developers can specify the locale and formatting options when converting numbers to strings. For example, an object that enables Japanese yen formatting can be instantiated as follows:

and it can produce strings like "￥123,457".
charte.ca does not provide any programming platform for chart creators, but it allows to pass the locale 'ja-JP' and the option object { style: 'currency', currency: 'JPY' } as additional parameters to the {value} keyword used in axis marks, data labels and callouts. The convention is to extend the "value" keyword with a semicolon followed by the number format specification:

NumberFormat:{locale:'<desired locale>', options:<desired options>}For example:{value;NumberFormat:{locale:'en', options:{useGrouping: true }}} will produce numbers with comma as a thousands separator{value;NumberFormat:{locale:'en-US',options: style:'currency',currency:'GBP',minimumFractionDigits:4}}} will produce British pound amounts with 4 digits after decimal point.In the example below, the callout format{series}: {value;NumberFormat:{locale:'en', options:{useGrouping: true }}}is specified, which makes the callout for the "0-4" age group with value 1453708 to be formatted as "0-4: 1,453,708":

Sunday, May 7, 2017

Great news: charte.ca now supports comparative histograms. This kind of charts comes handy when you want to compare two or more groups of series side-by-side. In most cases, this type of charts is used to draw a population pyramid, but it has other uses as well.

The following chart shows country population by age group, for multiple years, comparing male and female population.

Friday, January 6, 2017

I was curious about the differences between American and Canadian immigration systems. After 2016 US elections, we hear a lot about those differences, but I could not find a good source with actual numbers compared. Let's do it here. As usual, here is the Google Docs spreadsheet with all relevant data. As usual, all charts below are interactive, just move your mouse over the line or the legend item.

Let's start with the simplest part - total population numbers provided by Wikipedia:

No surprises here - these countries are economically and culturally close, so population growth patterns are similar.